C＃WPF ChartingToolKit：如何在MouseRightButtonDown中从ColumnSeries获取独立轴值？

Question

我有一个数据绑定到它的ColumnSeries，它显示正确。当右键单击列时，我想知道独立轴（X）值是多少。理想情况下，我想显示带有这些信息的上下文菜单。

我有一个MouseRightButtonDown处理程序，但无法弄清楚如何执行命中测试来获取X轴信息。

我已启用选择，但不希望在右键单击之前选择列。

任何帮助，将不胜感激！

Answer 1

下面是可用的示例代码。

MainWindow.xaml：

<Window x:Class="ColumnSeriesApp.MainWindow" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
      xmlns:chartingToolkit="clr-namespace:System.Windows.Controls.DataVisualization.Charting;assembly=System.Windows.Controls.DataVisualization.Toolkit" 
    xmlns:local="clr-namespace:ColumnSeriesApp" 
     Title="Pet Data" Height="350" Width="525"> 

MainWindow.xaml.cs：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Windows; 
using System.Windows.Controls; 
using System.Windows.Data; 
using System.Windows.Documents; 
using System.Windows.Input; 
using System.Windows.Media; 
using System.Windows.Media.Imaging; 
using System.Windows.Navigation; 
using System.Windows.Shapes; 

namespace ColumnSeriesApp 
{ 
/// <summary> 
/// Interaction logic for MainWindow.xaml 
/// </summary> 
public partial class MainWindow : Window 
{ 
    public PetData m_PetData; 
    public MainWindow() 
    { 
     m_PetData = new PetData(); 
     DataContext = m_PetData; 
     InitializeComponent(); 
    } 

    private void m_colserHistogram_MouseRightButtonDown(object sender, MouseButtonEventArgs e) 
    { 
     // Figure out what column we are on and display a popup menu based on the information. 
     IInputElement ieMouseOver = e.MouseDevice.DirectlyOver; 
     Rectangle rMouseOver = (Rectangle)ieMouseOver; 
     string strMouseOverContext= rMouseOver.DataContext.ToString(); 
     string strMouseOverKey= ""; 
     foreach (var vKvP in m_PetData) 
     { 
      if (1 == strMouseOverContext.IndexOf(vKvP.Key)) 
       strMouseOverKey = vKvP.Key; 
     } 

     if (!String.IsNullOrEmpty(strMouseOverKey)) 
      MessageBox.Show("The X value is " + strMouseOverKey); 
    } 
} 

public class PetData : Dictionary<string, int> 
{ 
    public PetData() 
    { 
     Add("SallyBeagle", 7); 
     Add("Cujo", 10); 
     Add("DobyDeedle", 11); 
     Add("Caramel", 6); 
     Add("Boo", 6); 
    } 
} 
} 

这似乎工作得很好。如果瑞克没有回来的想法，我可能会放弃寻找一段时间 - 感谢动机！

现在 - 这个解决方案全部是MVVM和什么？它仍然感觉有点像一个黑客....

Answer 2

您可以在视觉树上寻找ColumnDataPoint。

这里的一个示例图表：

<Grid MouseLeftButtonDown="Grid_MouseLeftButtonDown"> 
    <Grid.Resources> 
     <PointCollection x:Key="sampleData"> 
      <Point X="1" Y="6"/> 
      <Point X="2" Y="4"/> 
      <Point X="3" Y="8"/> 
     </PointCollection> 
    </Grid.Resources> 
    <chartingToolkit:Chart Title="Chart Title"> 
     <chartingToolkit:ColumnSeries Name="chart1" Title="Column Series" ItemsSource="{StaticResource sampleData}" IndependentValueBinding="{Binding X}" DependentValueBinding="{Binding Y}"/> 
    </chartingToolkit:Chart> 
</Grid> 

和与该代码隐藏：

private void Grid_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
{ 
    var element = Mouse.DirectlyOver as DependencyObject; 
    while (element != null && !(element is ColumnDataPoint)) 
    { 
     element = VisualTreeHelper.GetParent(element); 
    } 
    if (element != null) 
    { 
     var columnDataPoint = element as ColumnDataPoint; 
     Debug.WriteLine("X = " + columnDataPoint.IndependentValue); 
     Debug.WriteLine("Y = " + columnDataPoint.DependentValue); 
    } 
} 

的X和Y值处的项目的鼠标在将被打印输出的鼠标左键时按钮被点击。